Battered and grooved Tethys

24 November 2004

Having passed closer to Tethys than the Voyager 2 spacecraft, the NASA/ESA/ASI Cassini-Huygens spacecraft has returned the best-ever natural colour view of this icy Saturnian moon.

The battered surface of Tethys (1060 kilometres across) seen here has a neutral hue, and is a mosaic of two Cassini-Huygens 'footprints'. Three images taken in the red, green and blue filters were taken to form a natural colour composite.

The result reveals a world nearly saturated with craters - many small craters lie on top of older, larger ones, suggesting an ancient surface. At the top and along the boundary between day and night, the moon's terrain has a grooved appearance.

This moon is known to have a density very close to that of water, indicating it is likely composed mainly of water ice. Its frozen mysteries await Cassini's planned close fly-by in September 2005.

The Cassini-Huygens mission is a co-operative project of NASA, ESA and ASI, the Italian space agency.